You can install all versions of php either from source or install the default version using yum installer.
My server has php5.3 already installed and I am going to install PHP5.6 from source.
Create required folders
mkdir -p /usr/local/php56
mkdir -p /etc/php56
mkdir -p /etc/php56/php.d
./configure –prefix=/usr/local/php56 –with-config-file-path=/etc/php56 –with-config-file-scan-dir=/etc/php56/php.d –with-libdir=lib64 –with-mysql –with-mysqli –enable-mbstring –disable-debug –disable-rpath –with-bz2 –with-curl –with-gettext –with-iconv –with-openssl –with-gd –with-mcrypt –with-pcre-regex –with-zlib –enable-soap –enable-sockets –enable-zip –enable-bcmath –enable-calendar –enable-exif –enable-gd-native-ttf –with-freetype-dir –with-jpeg-dir –with-png-dir
Notes: You may see errors that few packages were not installed. In most case you will need to install devel packages.
eg: yum install libjpeg-turbo-devel
yum install libxml2-dev
yum install bzip2-devel
You need to compile it again after installing the packages.
Copy php.ini file
cp php.ini-production /usr/local/php56/php.ini
In order to enable multiple PHP versions, we need to install suphp on the server. I assume the server has suphp configured already. Make the following changes
edit the file /etc/suphp.conf and add the line
Edit the file /etc/httpd/conf.d/php.conf and add following lines
Enable PHP5.6 for a folder/site
create an .htaccess file and add following line
AddHandler application/x-httpd-php56 .php